All-in-focus imager using white-light interferometry

The patent segments the imaging process into multiple focal planes, capturing images at different depths and then combining them computationally. This allows each individual image to be captured with optimal focus at its specific plane while the combined result provides extended depth of focus, resolving the contradiction between high resolution (requiring low F/#) and large depth of focus.

The patent transitions from two-dimensional lateral imaging to three-dimensional volumetric imaging by adding the depth dimension. Multiple images captured at different focal planes are combined to create an all-in-focus image that encompasses the entire depth range, effectively adding a temporal dimension (sequential capture at different planes) to achieve extended depth of focus while maintaining high lateral resolution.

Instead of using a single slow optical system with high F/# that compromises lateral resolution, the patent segments the depth range into multiple planes and captures images at each plane using a fast optical system with low F/#. This maintains high lateral resolution in each individual image while the combination of multiple images provides the extended depth of focus that would otherwise require a slow optical system.

The patent maintains continuous useful action by capturing images across the entire depth range through sequential focal plane adjustments. Each captured image contributes useful information about a specific depth plane, and the computational combination of all these images produces the final all-in-focus image, ensuring that the fast optical system operates continuously at optimal resolution settings throughout the imaging process.

The patent replaces slow mechanical scanning systems (as used in confocal microscopy) with a faster computational approach. Instead of physically scanning through the entire depth range point-by-point or plane-by-plane using mechanical stages, the system uses a fast camera to capture multiple focal planes in rapid succession and then applies computational algorithms to combine them, significantly improving operation speed while maintaining extended depth of field capability.

The patent employs periodic adjustment of the focal plane positions, systematically moving through discrete depth planes in a periodic sequence. This structured periodic action allows the fast camera to capture each plane at optimal focus while maintaining a predictable and efficient imaging rhythm, improving overall operation speed compared to continuous scanning methods.

The patent makes the imaging system universal by enabling it to perform both extended depth of field imaging and true-color capture simultaneously. The fast optical system with low F/# captures full-color information at each focal plane, and the computational combination process preserves color data throughout, making the system multi-functional: it achieves extended depth of field like interferometric methods while maintaining the color imaging capability that traditional interferometry lacks.

The patent performs preliminary color capture at each focal plane before the computational combination step. By ensuring that full-color information is recorded in the raw images from the fast camera system, the subsequent processing can combine these color-rich images to produce the final all-in-focus color image, preserving color capability throughout the extended depth of field imaging process.